Portable cutting machine



Jan. 29, 1935. A, B. THOMPSON ET AL PORTABLE CUTTING MACHINE Original Filed June 30, 1928 g vvuwntoz; 0277,3501? Err/w 5. 772

ZUz'ZZz'cmz D. Gran/e5 Patented Jan. 29, 1935 uni-TED STATES 1,989,120 PORTABLE corms. IMA'CHINE Arthur .13. Thompson and William .D. Graves, Seattle, Wash, assignors, by direct and mesne V assignments, to International Register Com- Daily, Chicago, 'Ill.,"a corporation of Illinois I Application June 30,1928, Serial No. 289,394 Renewed December 17, 1934 10 Claims.

Our invention relates to machines designed -for cutting sheet *material :and consists of a portable, power driven idevice, operable as a hand tooland capable of icutting :sheet material in any pattern 5 desired.

The object of our invention is to :produce a device of the sort which shall :be of asimple, cheap and'durable construction, easilymanipulated and also one in which the center of gravity isflowlso that it will be difiicult to overturn.

The specific purpose for whichthis machine has been designed, is the cutting of Beaver board? It is, h'owever, e'qually'we'll adapted to the cutting of a wide range of materials.

In the accompanying drawing we have shown the machine constructed in conformity with that of one whioh'we have -built and pr actically open sited.

Figural is aside elevationof the machine.

Figure 2 is a front elevation.

' Figure? is a vertical section taken on a plane which includes :the reciprocating lmife-oarrying bar and the' head of the machine.

Figure 4 is a planet the cutting-parts of the machine, the head being in section through its lower part. I

Figure '5 is a. sectional plan of the' head illustrating the means employed to hold the cutting bar'from turning. a I

The machine organized as illustrated is mounted'upon a flat base 1, which has an opening 10 towards one 'end "in which the cutter'operat'es. This 'base is designed to rest upon the material being-cut and to be slid thereover after the manner'of movement of an-iron over cloth.

The base has mounted thereon a post 2, towards the top of which is 'journaled a pulley 20 carrying at one end of its shaft a crank disk or arm 21 and a crank pin 22 to which is connected aconnecting rod 23. This rod is conneeted bya ball-and-socket joint '24 with the upper end of the knife or cutter "carrying bar 25, which bar is mounted for vertical reciprocation in -a guide 226 which projects from the post lorhea'd 12.

Secured to the lower end of bar 25 isa cutter carryingihead 3, having :secured thereto the knife or nutter 30. The latter is onset to one :side of the axis 'of the reciprocating bar .25 :and under certain conditions may swing said bar 125 about itsaxis. The opening :10 in the base plate is of a size to permit such swinging.

The cutter head 3 has mounted thereon for vertical reciprocation a rod 31 which functions as an operating guide and a presser foot. It is held down by springs 32 so as to be at all times in contact with the work.

The pulley 20 is turned from a small pulley 41 through a belt 42, pulley 41 being on the shaft 40 of a small electric motor 4 mounted upon the base plate 1. Any other suitable means for connecting the motor with the pulley 20 may beemplayed. -In the drawing .5 represents the sheet being cut. 7

Connecting the upper part of the :postor .head

with casing of motor 4, is a bar 6 which functions asia handle'whereby to control the device.

it may "at times ile desirable to prevent-turm ing-of the reciprocating bar 25. In Figure 5 we have shown how this may be done. Passing throughthe guide arm 26, transversely of and to slightly intersect the bore which receives the bar 25, is a boreyinwhich is mounted :a locking bar 7.. This 'bar has a fiat spot '70 -on-one side positioned to register with the bar 25, and bar 25 has-a similar flat-section 7-1-of'a ieng-thoorrespending with the length of its stroke. I dtl'hen locking-bar '7 is turnedto-preseritits flat spot to the bar 25, the bar 25 may turn freely, When, however, the locking bar I7 is turned to present its uncut side to the bar 25, whichcan be .done onlywhen theflat spot 1 1 is toward bar '7, the bar 25 may reciprocate but cannot turn. To hold the locking bar '7 in a'd justed position its projecting end :may be given two flat surfaces 75 and'376 which may be engagedby aspringzarm 72;. Theslocking bar 7 may be given a bent end toiform=an:operatingarm 73.

-One object we have had in mind in designing this machine is to 'keep the centerof gravity of the machine low, so that dangerof tipping over-is minimized. To this end we :have placed the motor cl'ose jdown to the base plat-sand have extended the drive upia'long the post, as by the belt 512. We have also located the handle above the motor, supporting one end from the .motor-casing and the other from the poster head, :2. This keeps. the center of gravityiow, permits use of a light post-or head 2, as-it has noparticular weight to 'carry,'.'keeps the view of the working point on obstructed by the motor and keeps the handle uncovered and engageable without-interference of other :parts.

When commencing a cut, the device is placed upon the material to be ent, the base i resting upon its upper suriace, and acting asa stripper, to prevent the material rising with the cutteras the latterireciprocates. 'The:presser:31-=also functions as a iocal stripper. Now the handle '6 is grasped and the device .moved bodily along the line of out marked on the :material. Since the cutter 3'0 and presser 31 :are offset from. the axis of the cutter bar 25, and normally are free to swivel thereabout, the drag of the material on the presser 31, with which it is always in contact, causes them to lie directly rearwardly of the direction in which the axis of the cutter bar 25 happens to be moving. Thus, by moving the device, through the handle 6, to one side or the other, or backwards, the presser and the cutter are caused to turn and follow anygiven curve or line. The drag of the presser 31, behind the cutter 30, insures that the line of forward movement of the cutter will always lie substantially in a line which includes the axis of the presser and the bar 25, which latter is in advance of the presser 31.

What we claim as our invention is:

1. A cutting machine having a base adapted to rest upon and move over the work, a motor mounted upon the base, a head extending up ward from one end of the base, a cutter bar mounted for reciprocation upon said head, means for reciprocating said bar by the motor, a cutter carrying head mounted upon the cutter bar to swing about the axis of said bar, a cutter carried by said head laterally spaced from its pivot axis, and means for locking said head against swinging when desired.

' 2. Ina portable cutting machine of the type described, a reciprocating cutter bar, a cutter head mounted to swing freely about the axis of said cutter bar, a cutter carried upon said cutter head laterally spaced from said bar, and a locking key carried by said head adjustable to lock said cutter head against turning upon the cutter bar axis or to swing freely thereon as desired.

3. In a cutting machine of the character described, 21. base having a smooth planar under surface of considerable extent and adapted to rest upon and move over the work, a motor mounted on the base, a head extending upward from one end of the base, a cutter bar mounted for reciprocation upon said head, driving connections between said bar and said motor comprising means permitting free turning of said bar on its axis, a cutter carrying head secured upon the lower end of the cutter bar, a cutter carried by said head eccentric to said bar, and means for locking said bar against turning when desired.

4. In a cutting machine of the character described, a base having a smooth planar under surface of considerable extent and adapted to rest on and move over the work, a motor mounted on the base, a head extending upward from one end of the base, a cutter bar mounted for reciprocation upon said head, driving connections between said bar and said motor comprising a connecting rod and a ball and socket connection between said rod and the upper end of said bar permitting free turning of the latter on its axis, a cutter carrying head secured upon the lower end of the cutter bar, a cutter carried by said head eccentric to said bar, and means for locking said bar against turning when desired.

5. In a cutting machine of the character described, a base having a smooth planar under surface of considerable extent and adapted to rest on and move over thework, a motor mounted on the base, a head extending upward from one end of the base, a cutter bar mounted forreciprocation upon said head,'driving connections between said bar and said motor comprising means permitting free turning of said bar on its axis, a cutting tool securedto the lower end of said bar for reciprocation and turning movement therewith, and means for turning said baron its axis in accordance with change in direction of movement of said base over the work.

6. In a cutting machine of the character described, a base having a smooth planar under surface of considerable extent and adapted to rest on and move over the work, a motor mounted on the base, a cutter bar mounted for reciprocation substantially perpendicular to said base and free to turn on its axis, driving connections between said motor and said bar, a cutting tool secured to the lower end of said bar for reciprocation and turning movement therewith, and means for turning said bar on its axis in accordance with change in direction of movement of said base over the work.

7. In a cutting machine of the character described, a base having ,a smooth planar under surface of considerable extent and adapted to rest on and move over the work, a motor mounted on the base, a cutter bar mounted for reciprocation substantially perpendicular to said base and free to turn on its axis, driving connections between said motor and said bar, means for securing a cutting tool to the lower end of said bar for rea ciprocation and turning movement therewith, and means for turning said bar on its axis in accordance with change in direction of movement of said base over the work.

8. In a cutting machine of the character described, a base having a smooth planar under surface of considerable extent and adapted to rest on and move over the work, a motor mounted on the base, a cutter bar mounted for reciprocation substantially perpendicular to said base and free to turn on its axis, driving connections between said motor and said bar, and means for securing a cutting tool to the lower end of said bar for reciprocation and turning movement therewith.

9. In a cutting machine of the character described, a base having a smooth planar under surface of considerable extent and adapted to rest on and move over the work, a motor mounted on the base, a cutter bar mounted for reciprocation substantially perpendicular to said base and free to turn on its axis, driving connections between said motor and said bar, means for securing a cutting tool to the lower end of said bar for reciprocation and turning movement therewith, and means for locking said bar against turning when desired.

10. In a cutting machine of the character described, a base having 'a smooth planar under surface of considerable extent and adapted to rest on and move over the work, a motor mounted on the base, a cutter bar mounted for reciprocation substantially perpendicular to said base and free to turn on its axis, driving connections between said motor and said bar, a cutter carrying head secured to the lower end of said bar for reciprocation and turning movement therewith, a cutter carried by said head eccentric to said bar, and means for locking said bar against turning movement when desired.

ARTHUR B. THOMPSON. WILLIAM D. GRAVES. 

